Al-Munafiqun (The Hypocrites)

Surah 63 · Verse 3

That is because they believed then became infidels, so a seal was set on their hearts, therefore they do not understand.

ذَٰلِكَ بِأَنَّهُمْ آمَنُوا ثُمَّ كَفَرُوا فَطُبِعَ عَلَىٰ قُلُوبِهِمْ فَهُمْ لَا يَفْقَهُونَ